Balsalazide is a colon-specific, non-steroidal, anti-inflammatory aminosalicylate derivative which is useful in the treatment of gastrointestinal diseases, for example active ulcerative colitis and colon cancer (see WO 95/18622).
Balsalazide suffers from the disadvantage that a relatively high dose is required which makes it difficult to administer as a single dose. It is highly coloured and hence its administration as a solution is disadvantageous because it would stain the mouth. For compliance reasons the number of capsules to be swallowed by a patient per day should be as small as possible. When balsalazide is formulated as a capsule, the capsule has to be of such large dimensions that it is difficult, or impossible in some cases, to swallow whole.
A new formulation for balsalazide has now been found which solves or mitigates these problems.